i have seen this a couple of times on my customers cars.
one had been parked in the street near where a new block of units were being painted on a windy day. was an old car so the guy didnt care. thought it was funny to have a spotted car.
another was a week old mica red mazda 3 st/i. lady hadn`t noticed till i showed her. she was spewin.
she tracked it down that her teenage son had decided to paint his pushy in the garage the night before.
the paint mist had floated around and settled all over the new car.
i was able to polish most of it off the paint with a lot of elbow grease and a collection of Meguirers products.
the glass you can clean with super fine steel wool - 00 grade - or a razor blade scraper [ when using a scraper always use a new blade and plenty of soapy water so you dont scratch the glass ].
not sure how to get it off the plastic ?????? maybe a plastic welder might have some ideas for that.